The invention relates to a shock-absorbing shoe construction, particularly applicable to light-weight athletic shoes of the general variety popularly known as sneakers.
Foot comfort for the athlete and for those who jog or walk briskly for general exercise has been the target of many and varied proposals for shoe construction. And the broad concept of using a pneumatic cushion as part of the heel and/or sole construction has been known for the better part of a century, illustratively through King U.S. Pat. Nos. 541,814 of 1895 and Maddocks 1,011,460 of 1911. In more recent years, efforts have been directed to providing substantially uniformly absorbent action along the full length of the foot, either by employing specially fabricated pneumatic sheet material (as in Sindler U.S. Pat. 2,100,492), or by incorporating a full-length inflatable bladder in the sole (as in Reed U.S. Pat. Nos. 2,677,904 and in Cortina 2,863,230), or by providing an outsole with a substantially uniform distribution of air-filled cavities over the full area of the sole (as in Gardner U.S. Pat. Nos. 4,012,855, Petrosky 4,129,951, Khalsa, et al. 4,133,118, Moss 4,170,078, and Doak 4,397,104), or by providing a tread characterized by a distributed plurality of resilient "posts" served by interconnecting channels and a common source of pneumatic pressure (as in Muller U.S. Pat. No. 4,319,412). European Pat. No. 0,032,084 and German Provisional Patent Offenlegungsschrift No. OS 2,460,034 are illustrative of various arrangements to so construct the sole as to enable pneumatic preloading of all or selected regions of the foot.
These more recent structures are unduly complex, and they do not recognize or provide for the kind of distributed shock-absorbing resilience which is needed for alternating or intermittent jog/walk exercise.